The wild, rushing waters of India's Brahmaputra river guide Jane Archer
through the Kaziranga National Park, while an elephant ride leads to an
encounter with a Bengal tiger

The baby elephant that had been trailing its mother since the start of our safari began squealing, panic in its tone. Mum – on whose back I was riding – responded with loud trumpeting and headed into the long elephant grass after her baby.

“Tiger,” murmured the mahout.

I was on a river-cruise safari excursion to the Kaziranga National Park, a World Heritage Site in the floodplains that flank the banks of the Brahmaputra. The most prized inhabitant of Kaziranga is the greater one-hornedIndian rhinoceros, but the park is home to as many as 180 different mammals, including wild elephants, deer, bison and tiger. At the mention of the word, mild panic ensued. Excited at the thought of seeing the big cat so close, I wasn’t entirely sure I wanted to do so while on the back of a mother elephant intent on protecting her baby.

It’s an overused term but the Brahmaputra really does deserve the accolade “unique”. It’s the fastest-flowing waterway in the world and blazes such a trail through Assam that the landscape changes by the hour. Sandbanks come and go, water levels visibly rise and fall and the island of Majuli, once the largest inhabited river island in the world, is now the second largest due to erosion and the effects of a huge flood in 2012 (although it still has the largest population of any river island, with some 200,000 people squeezed into its 200 or so square miles).

One evening we tied up to a sandbank – the river is not navigable at night – and I watched as the sand was washed into the rushing river at an alarming rate. By the following morning the river had risen two feet. The crew was forced to move the makeshift gangway they had built for us to go ashore (that morning’s yoga, usually held on the top deck, was moved to the island) and the anchor of the survey boat that was guiding us downriver, which had been buried in sand when we docked, was now in deep water.

“The river gives and takes back elsewhere,” Sanjay Basu told me. Basu owns Far Horizon Tours, the India-based holiday company that operates the Mahabaahu, the boat I was sailing on. The fact he got this cruise up and running despite red tape that more than once threatened to strangle the project bears testament to his undisguised love and respect for the river, and his determination to bring the Brahmaputra, meaning “son of Brahma” in Sanskrit, to the attention of the wider world.

The river rises near Mount Kailash in the Himalayas, winds its way 807 miles east through the mountains of Tibet and then curls around, like the bend in a question mark, cutting through some of the world’s deepest canyons before heading south to join the Ganges in Bangladesh. Its total length is just shy of 2,000 miles.

Around half of the year’s annual monsoon rainwater falls in the Brahmaputra valley, and almost half of the meltwater from the Himalayas also dumps into the river. During monsoon season, from June to September, the river swells from 6.2 miles wide to more than 18 and becomes unnavigable, forcing the Mahabaahu into dry dock.

A fisherman off the island of Majuli

Unremarkable when viewed from the river bank, the ship’s comfortable and informal style was far more suited to this voyage through India than a boat offering five-star trappings would have been. Not that there weren’t niggles – none of the cabin televisions worked, the air-conditioning unit in my room was impossible to control so I either boiled or froze, and the shade canopy on the ship’s top deck was just a little too fragile for comfort.

But these were small beer when set against the positives: charming Indian crew who kept the cabins spotless and welcomed us back from trips ashore with cold drinks and towels, powerful showers with plenty of hot water, and Indian food that never failed to impress. Excursions were included in the cruise price and Shagzil, the cruise tour director, and Payal, a naturalist sailing with us, gave daily talks about the route’s history, culture and wildlife.

My seven-day trip started with a day in Delhi, and a cycle rickshaw ride through the Kinari Bazaar (“The biggest thing you learn in India is patience,” my guide Ritu told me, as we were swallowed up by a seething mass of people and bicycles that made the M25 look like child’s play), before a flight to Dibrugarh in Assam state.

From the airport it was a four-hour drive by Jeep to where the Mahabaahu was docked at Nimati.

Just days after my trip a new air service opened from Delhi to Jorhat Airport (you can also fly via Kolkata), which is one hour from Nimati and cuts out the need for the long drive, but I was fascinated by the organised chaos of India, watching as our driver dodged people, animals, cars, bikes and lorries non-stop for four hours. Mind you, there was also plenty of time to experience Indian driving the next day, as we were back in the Jeeps for a full-day excursion to see remains from the Ahom Kingdom, a dynasty that ruled here from the 13th to the 19th century, when the British took over, as well as a Hindu temple and a tea plantation.

Over the next seven days we visited monasteries and temples and toured villages without electricity where tourists were such an unusual sight that young lads were excitedly taking our pictures (the phones charged using solar panels). In the village of Luit Mukh, home to the Mishing people, the locals put on an impromptu dance and then all trooped down to the shore (landings most days were by small craft) to wave goodbye.

A rare Bengal tiger

In the evenings, passengers – my co-travellers were a friendly bunch from the Britain, Australia and Italy – would mingle in Mahabaahu’s bar and restaurant, discussing the day’s highlights as we tucked into the delicious Indian food served for breakfast, lunch and dinner (western options were always provided as well).

Even for seasoned travellers the journey was full of surprises. But the area’s ace was Kaziranga – 166 square miles of elephant grass populated by bird and wildlife. One afternoon we took a boat safari along the Dhansari River, a tributary of the Brahmaputra, following the edge of the park and, incredibly, spotted a Bengal tiger. As there are only about 60 inhabiting the park, the odds were probably a million to one. Such is Kaziranga’s scale, it was another two days before we set off on our elephant-back safari.

The 4am start was worth the effort to get close to the rhino, buffalo, vultures and deer that inhabit Kaziranga. And of course there was that close encounter with another tiger that had so upset our baby elephant, which actually turned out to be a close encounter with the very recent remains of a tiger’s breakfast. I felt for the deer (at least that’s what the mahout identified it as), but having seen the teeth on the tiger we disturbed two days previously, I was also just a little relieved that he had not hung around for dessert.

Jane Archer travelled with Perl River Cruises (01252 714477; perlrivercruises.com). A seven-night cruise from Nimati to Guwahati costs from £1,575 per person, cruise-only, departing on February 8, 2015. The price includes one night in a hotel in Delhi.

India essentials

You’ll need rupees for any souvenir shopping. Ask for small denomination notes when you change your money. (and note that vendors do not want US dollars).

Mosquitoes were not a problem on my cruise but best to take repellent just in case.

Pack your swimming gear - a dip in the ship’s pool is a refreshing end to a day’s sightseeing.

Dress code is casual at all times. Pack light clothes and suncream.

Pack comfortable flat shoes as you’ll be walking on uneven paths and climbing in and out of small tenders.